The site, located 430 metres north of the river, marks a spot where a bridge once crossed according to the Down Survey maps of 1655-6. Until recently, the castle’s location sat in the northeast corner of a farmyard, though the farm buildings themselves have since been demolished; satellite imagery from 2015 shows large farm sheds near the site that had vanished by 2017.

The castle appears on historical maps under various spellings and names. The Down Survey recorded it as ‘Enessnagge’ castle within Enishnagge Parish, whilst the first Ordnance Survey map of 1839 labelled it ‘Coortaur Castle (in ruins)’, a name that local historian Carrigan later dismissed as a misprint for ‘Court or Castle’. By 1948, the OS maps simply marked a cross indicating ‘Ennisnag Castle (Site of)’. The 25-inch Ordnance Survey maps from the 19th century showed three walls still standing, with only the north wall missing.

When the Ordnance Survey Letters documented the site in 1839, they described a modest structure measuring roughly 8.8 by 5.8 metres, with walls 1.8 metres thick. Parts of the east and south walls remained at that time, along with what they called ‘the butt of a small round tower’ at the southwest angle. By 1905, Carrigan noted that whilst the castle had been mostly taken down, ruins still stood several feet high. Today, no trace of these medieval walls can be seen at ground level, leaving only historical records and old maps to tell the story of this lost stronghold by the Kings River.